Astronauts completed their second spacewalk in under a week on Wednesday to replace old batteries outside the International Space Station.
Cmdr. Chris Cassidy and Bob Behnken quickly tackled the big, boxy batteries. For every two outdated batteries coming out, a new and improved one goes in to supply power to the orbiting station on the night side of Earth.
Within a couple hours, the astronauts had installed another new battery, the third one in this latest series of spacewalks. NASA plans to send the pair out twice more in July to complete the battery swap-outs that began in 2017. The new lithium-ion batteries should last the rest of the space station's life, according to officials.
With their main chore completed, Cassidy and Behnken jumped ahead to loosen the bolts on the batch of old batteries coming out next time and remove other equipment. Some of the bolts required extra muscle, and another stubborn mechanism just wouldn't come off.
"Boy, it put up a good fight," Cassidy radioed. "These batteries — they like their home."
The astronauts had enough time to route power and ethernet cables outside the 420-kilometre-high outpost before the six-hour spacewalk drew to a close.
"Good thing there's an Earth down there" to tell up from down, Cassidy said.